The single-worker upload queue introduced head-of-line blocking: one slow
upload (LoTW signing via TQSL, or a service on a 30 s timeout) stalled the
whole queue, so every following QSO's Club Log upload waited and the rows sat
at "R". Operators on the older, concurrent build had no such problem — the
tell that this was a fresh regression.
Back to one goroutine per upload (never serialised), so a slow upload never
holds up the rest, while keeping the transient-failure retry with back-off
(concurrent, so it can't block anything).
rouggy
816c6ffcf1